Tài liệu Báo cáo khoa học: "Discriminative Word Alignment with Conditional Random Fields" ppt

... many-to-one word alignments, where each source word is aligned with zero or one target words, and therefore each target word can be aligned with many source words. Each source word is labelled with ... one-to-many alignments, where each target word is aligned with zero or more source words. Many-to-many alignments are recoverable using the standard techniques for superimposi...

Ngày tải lên: 20/02/2014, 11:21

... a method based on conditional random fields (CRFs). The models are encoded as determin- istic weighted finite state automata, and are applied by intersecting the automata with word- lattices that ... substantial improvements in accuracy for tagging tasks in Collins (2002). 2.3 Conditional Random Fields Conditional Random Fields have been applied to NLP tasks such as parsing (Ratn...

Ngày tải lên: 23/03/2014, 19:20

... list of all WordNet synonyms of the target word, under all its possible senses, and picking randomly one of the synonyms as the source word. For example, the word ‘disc’ is one of the words in the ... match the specified need the source words might be substituted with synony- mous target words. For example, given the source word ‘weapon’ a system may substitute it with the target syn...

Ngày tải lên: 20/02/2014, 12:20

... the interpretation of word senses. Different interpretations of word senses result in different so- lutions to word sense learning. One interpretation strategy is totreat a word sense as a set ... discovered tight clusters called committees by grouping top n words similar with target word using average- link clustering. Then the target word was assigned to committees if the simi...

Ngày tải lên: 20/02/2014, 16:20

... NER comprises a num- ber of word and POS tag features in a window of five words around the current word, along with a set of orthographic features defined on the current word. These are based on those ... 29.13 Label PER 40.49 Label O 60.44 Random 1 70.34 Random 2 67.76 Random 3 67.97 Random 4 70.17 Table 1: Development set F scores for NER experts 6.2 LOP-CRFs with unregularise...

Ngày tải lên: 31/03/2014, 03:20

... for clustering word instances, which is used in the multi-prototype ver- sion of our model that accounts for words with mul- tiple senses. We evaluate our new model on the standard WordSim-353 (Finkelstein ... context and one represen- tation per word. This is problematic because words are often polysemous and global con- text can also provide useful information for learning word meani...

Ngày tải lên: 19/02/2014, 19:20

... (2011) with as simpler system. 3 Evaluation In this paper, in order to be comparable with Wang et al. (2011), we evaluate our system against the corpora from the Second International Chi- nese Word ... density distributions for words vs. non-words, we observed that the VBE at both boundaries were the most dis- criminative value. Therefore, we decided to take in account the VBE only at t...

Ngày tải lên: 19/02/2014, 19:20

... constraint in word align- ment. That is, a word is not allowed to align to more than one word. This is a strong limitation as no idiom or multi -word expression is allowed to align to a single word ... constraint. Both ITG alignment 316 approaches with and without this constraint will be elaborated in Section 6. Secondly, the simple ITG leads to redundancy if word alignm...

Ngày tải lên: 20/02/2014, 04:20

... combination with describing morphemes by letter transitions. From the Ukwabelana corpus (Spiegler et al., 2010b) we sampled 2500 Zulu words with a single segmenta- tion each. 3.1 Learning with increasing ... t ji . It describes a word s segmentation by its morpheme boundaries and resulting letter transitions within morphemes. A boundary vector b j is found by evaluating each position i...

Ngày tải lên: 20/02/2014, 04:20

... de- fined with TARGET, thus this frequent token is also included in F . We use the set of frequent words F to generalize words to word classes”. We define a word class as either a word itself ... , w |s| , where w i is the i-th word of s, we generalize its words w i to word classes ω i as follows: ω i =  w i if w i ∈ F P OS(w i ) otherwise that is, a word w i is left unchanged i...

Ngày tải lên: 20/02/2014, 04:20